Added SAMA5D36 support.
Fixed building startup code when Soft floating point is selected.
Updated libchip_sama5d3x to that supplied in Softpack version 1.3.2.
Added ctl_lowest_isr_priority/ctl_highest_isr_priority/ctl_adjust_isr_priority/ctl_sleep/ctl_woken to SAMA5D3_ctl.c.
Fixed NESTED_INTERRUPT support in irq_handler.